[testsuite] test for weak_undefined support and add options

  A number of tests that depend on weak undefined symbols fail to
require that support, and arrange to skip some targets and add special
options to others on a test-by-test basis.  Fix this by stating the
requirement explicitly, and adding a proc to return any required
options.

Others rely on weak undefined symbols only to test for the
availability of posix_memalign.  Drop that in favor of dg effective
target support for posix_memalign.

Regstrapped on ppc64-linux-gnu.  Also tested (with gcc-12) on multiple
*-vxworks7r2 targets (arm, aarch64, ppc64, x86, x86_64).  Ok to install?


for  gcc/testsuite/ChangeLog

	* lib/target-supports.exp (add_options_for_weak_undefined):
	New.
	(check_effective_target_weak_undefined): Use it.
	(check_effective_target_posix_memalign): New.
	* gcc.dg/torture/pr53922.c: Drop skips and custom options in
	favor of effective target requirement and added options for
	weak_undefined symbols.
	* gcc.dg/torture/pr90020.c: Likewise.
	* gcc.dg/addr_equal-1.c: Likewise.
	* gcc.target/aarch64/aapcs64/aapcs64.exp: Likewise, for
	abitest.S-using tests.
	* gcc.dg/torture/pr60092.c: Likewise, but in favor of
	posix_memalign tests.
	* gcc.dg/vect/vect-tail-nomask-1.c: Likewise.
---
 gcc/testsuite/gcc.dg/addr_equal-1.c                |    5 ++--
 gcc/testsuite/gcc.dg/torture/pr53922.c             |   10 ++------
 gcc/testsuite/gcc.dg/torture/pr60092.c             |   12 ++-------
 gcc/testsuite/gcc.dg/torture/pr90020.c             |    7 ++---
 gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c     |   11 ++------
 .../gcc.target/aarch64/aapcs64/aapcs64.exp         |   17 ++++++++-----
 gcc/testsuite/lib/target-supports.exp              |   26 ++++++++++++++++++--
 7 files changed, 44 insertions(+), 44 deletions(-)
  

On Mar 15, 2023, Alexandre Oliva <oliva@adacore.com> wrote:

> Regstrapped on ppc64-linux-gnu.  Also tested (with gcc-12) on multiple
> *-vxworks7r2 targets (arm, aarch64, ppc64, x86, x86_64).  Ok to install?

Further testing revealed a problem in my attempted use of lappend in
aapcs64.exp, in the previous version of the patch.  Fixed in this one,
retested on aarch64-vxworks7r2.  Ok to install?


for  gcc/testsuite/ChangeLog

	* lib/target-supports.exp (add_options_for_weak_undefined):
	New.
	(check_effective_target_weak_undefined): Use it.
	(check_effective_target_posix_memalign): New.
	* gcc.dg/torture/pr53922.c: Drop skips and custom options in
	favor of effective target requirement and added options for
	weak_undefined symbols.
	* gcc.dg/torture/pr90020.c: Likewise.
	* gcc.dg/addr_equal-1.c: Likewise.
	* gcc.target/aarch64/aapcs64/aapcs64.exp: Likewise, for
	abitest.S-using tests.
	* gcc.dg/torture/pr60092.c: Likewise, but in favor of
	posix_memalign tests.
	* gcc.dg/vect/vect-tail-nomask-1.c: Likewise.
---
 gcc/testsuite/gcc.dg/addr_equal-1.c                |    5 ++--
 gcc/testsuite/gcc.dg/torture/pr53922.c             |   10 ++------
 gcc/testsuite/gcc.dg/torture/pr60092.c             |   12 ++-------
 gcc/testsuite/gcc.dg/torture/pr90020.c             |    7 ++---
 gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c     |   11 ++------
 .../gcc.target/aarch64/aapcs64/aapcs64.exp         |   17 ++++++++-----
 gcc/testsuite/lib/target-supports.exp              |   26 ++++++++++++++++++--
 7 files changed, 44 insertions(+), 44 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/addr_equal-1.c b/gcc/testsuite/gcc.dg/addr_equal-1.c
index 35fa0102e3063..db65dea4a8d2a 100644
--- a/gcc/testsuite/gcc.dg/addr_equal-1.c
+++ b/gcc/testsuite/gcc.dg/addr_equal-1.c
@@ -1,9 +1,8 @@
-/* { dg-do run { target { nonpic || pie_enabled } } } */
-/* { dg-require-weak "" } */
+/* { dg-do run { target { { nonpic || pie_enabled } && weak_undefined } } } */
 /* { dg-require-alias "" } */
 /* { dg-options "-O2 -fdelete-null-pointer-checks" } */
-/* { dg-skip-if "" { powerpc-ibm-aix* } } */
 /* { dg-skip-if "function pointers can be NULL" { keeps_null_pointer_checks } } */
+/* { dg-add-options weak_undefined } */
 void abort (void);
 extern int undef_var0, undef_var1;
 extern __attribute__ ((weak)) int weak_undef_var0;
diff --git a/gcc/testsuite/gcc.dg/torture/pr53922.c b/gcc/testsuite/gcc.dg/torture/pr53922.c
index b3f2c1a58f830..07359d6764964 100644
--- a/gcc/testsuite/gcc.dg/torture/pr53922.c
+++ b/gcc/testsuite/gcc.dg/torture/pr53922.c
@@ -1,11 +1,5 @@
-/* { dg-do run } */
-/* { dg-require-weak "" } */
-/* { dg-skip-if "No undefined" { *-*-mingw* } } */
-/* { dg-skip-if "No undefined weak" { *-*-aix* } } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* && { ! lp64 } } } */
-/* { dg-skip-if "No undefined weak" { nvptx-*-* } } */
-/* { dg-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-do run { target { weak_undefined } } } */
+/* { dg-add-options weak_undefined } */
 
 int x(int a)
 {
diff --git a/gcc/testsuite/gcc.dg/torture/pr60092.c b/gcc/testsuite/gcc.dg/torture/pr60092.c
index 74e7c174a8323..102ba6e0d9f87 100644
--- a/gcc/testsuite/gcc.dg/torture/pr60092.c
+++ b/gcc/testsuite/gcc.dg/torture/pr60092.c
@@ -1,12 +1,7 @@
-/* { dg-do run } */
-/* { dg-require-weak "" } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* && { ! lp64 } } } */
-/* { dg-skip-if "No undefined weak" { nvptx-*-* } } */
-/* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-do run { target { posix_memalign } } } */
 
 typedef __SIZE_TYPE__ size_t;
-extern int posix_memalign(void **memptr, size_t alignment, size_t size) __attribute__((weak));
+extern int posix_memalign(void **memptr, size_t alignment, size_t size);
 extern void abort(void);
 int
 main (void)
@@ -14,9 +9,6 @@ main (void)
   void *p;
   int ret;
 
-  if (!posix_memalign)
-    return 0;
-
   p = (void *)&ret;
   ret = posix_memalign (&p, sizeof (void *), -1);
   if (p != (void *)&ret)
diff --git a/gcc/testsuite/gcc.dg/torture/pr90020.c b/gcc/testsuite/gcc.dg/torture/pr90020.c
index 657c4ccfe45c4..40035aa758e6e 100644
--- a/gcc/testsuite/gcc.dg/torture/pr90020.c
+++ b/gcc/testsuite/gcc.dg/torture/pr90020.c
@@ -1,8 +1,5 @@
-/* { dg-do run } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* || powerpc-ibm-aix* } } */
-/* { dg-require-weak "" } */
-/* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-do run  { target { weak_undefined } } } */
+/* { dg-add-options weak_undefined } */
 
 void __attribute__((noinline,noclone))
 check (int i)
diff --git a/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c b/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c
index e5bbeaede095b..ee9ab2e9d910b 100644
--- a/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c
+++ b/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c
@@ -1,14 +1,10 @@
-/* { dg-require-weak "" } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* && { ! lp64 } } } */
-/* { dg-skip-if "No undefined weak" { nvptx-*-* } } */
-/* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-skip-if "No undefined weak" { ! { posix_memalign } } } */
 /* { dg-additional-options "--param vect-epilogues-nomask=1 -mavx2" { target avx2_runtime } } */
 
 #define SIZE 1023
 #define ALIGN 64
 
-extern int posix_memalign(void **memptr, __SIZE_TYPE__ alignment, __SIZE_TYPE__ size) __attribute__((weak));
+extern int posix_memalign(void **memptr, __SIZE_TYPE__ alignment, __SIZE_TYPE__ size);
 extern void free (void *);
 
 void __attribute__((noinline))
@@ -98,9 +94,6 @@ run_test ()
 int
 main (int argc, const char **argv)
 {
-  if (!posix_memalign)
-    return 0;
-
   run_test ();
   return 0;
 }
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp b/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
index 8cf9cc1e8e585..38a2c06a59560 100644
--- a/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
@@ -32,12 +32,15 @@ set additional_flags "-W -Wall -Wno-abi -fno-pie -no-pie"
 # Test parameter passing.  This uses abitest.S which relies on weak
 # symbols.
 
-if { [check_weak_available] } {
+set additional_flags_for_abitest [add_options_for_weak_undefined ""]
+set additional_flags_for_abitest "$additional_flags $additional_flags_for_abitest"
+
+if { [check_effective_target_weak_undefined] } {
     foreach src [lsort [glob -nocomplain $srcdir/$subdir/test_*.c]] {
 	if {[runtest_file_p $runtests $src]} {
 	    c-torture-execute [list $src \
 				    $srcdir/$subdir/abitest.S] \
-				    $additional_flags
+		$additional_flags_for_abitest
 	}
     }
 }
@@ -54,28 +57,28 @@ foreach src [lsort [glob -nocomplain $srcdir/$subdir/rec_*.c]] {
 
 # Test unnamed argument retrieval via the va_arg macro.  This uses abitest.S
 # which relies on weak symbols.
-if { [check_weak_available] } {
+if { [check_effective_target_weak_undefined] } {
     foreach src [lsort [glob -nocomplain $srcdir/$subdir/va_arg-*.c]] {
 	if {[runtest_file_p $runtests $src]} {
 	    c-torture-execute [list $src \
 				    $srcdir/$subdir/abitest.S] \
-				    $additional_flags
+		$additional_flags_for_abitest
 	}
     }
 }
 
 # Test function return value.  This uses abitest.S which relies on
 # weak symbols.
-if { [check_weak_available] } {
+if { [check_effective_target_weak_undefined] } {
     #   Disable -fipa-ra to prevent the compiler from generating
     #   conflicting code.
-    set additional_flags_for_func_ret $additional_flags
+    set additional_flags_for_func_ret $additional_flags_for_abitest
     append additional_flags_for_func_ret " -fno-ipa-ra"
     foreach src [lsort [glob -nocomplain $srcdir/$subdir/func-ret-*.c]] {
 	if {[runtest_file_p $runtests $src]} {
 	    c-torture-execute [list $src \
 				    $srcdir/$subdir/abitest.S] \
-				    $additional_flags_for_func_ret
+		$additional_flags_for_func_ret
 	}
     }
 }
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index fcfe290d07d71..ac6f000afd18e 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -356,6 +356,18 @@ proc check_weak_available { } {
     }
 }
 
+# return options to add to enable weak undefined symbols.
+
+proc add_options_for_weak_undefined { flags } {
+    if { [istarget *-*-darwin*] } {
+	lappend flags "-Wl,-undefined,dynamic_lookup"
+	if { [istarget *-*-darwin[89]*] } {
+	    lappend flags "-Wl,-flat_namespace"
+	}
+    }
+    return $flags
+}
+
 # return 1 if weak undefined symbols are supported.
 
 proc check_effective_target_weak_undefined { } {
@@ -365,7 +377,7 @@ proc check_effective_target_weak_undefined { } {
     return [check_runtime weak_undefined {
 	extern void foo () __attribute__((weak));
 	int main (void) { if (foo) return 1; return 0; }
-    } ""]
+    } [add_options_for_weak_undefined ""]]
 }
 
 ###############################
@@ -1154,6 +1166,16 @@ proc check_effective_target_clone {} {
     return [check_function_available "clone"]
 }
 
+# Return 1 if the target supports posix_memalign, 0 otherwise.
+proc check_effective_target_posix_memalign {} {
+    if { [istarget *-*-vxworks*] } {
+	# VxWorks doesn't have posix_memalign but our way to test
+	# can't tell as we're doing partial links for kernel modules.
+	return 0
+     }    
+    return [check_function_available "posix_memalign"]
+}
+
 # Return 1 if the target supports setrlimit, 0 otherwise.
 proc check_effective_target_setrlimit {} {
     # Darwin has non-posix compliant RLIMIT_AS
@@ -10827,7 +10849,7 @@ proc check_vect_support_and_set_flags { } {
         } else {
             set dg-do-what-default link
         }
-    } elseif [istarget "aarch64*-*-*"] {
+    } elseif [istarget aarch64*-*-*] {
         set dg-do-what-default run
     } elseif [istarget s390*-*-*] {
 	# The S/390 backend set a default of 2 for that value.
  

On Mar 15, 2023, at 11:40 PM, Alexandre Oliva <oliva@adacore.com> wrote:
> 
> On Mar 15, 2023, Alexandre Oliva <oliva@adacore.com> wrote:
> 
>> Regstrapped on ppc64-linux-gnu.  Also tested (with gcc-12) on multiple
>> *-vxworks7r2 targets (arm, aarch64, ppc64, x86, x86_64).  Ok to install?
> 
> Further testing revealed a problem in my attempted use of lappend in
> aapcs64.exp, in the previous version of the patch.  Fixed in this one,
> retested on aarch64-vxworks7r2.  Ok to install?

Ok.
  

On Mar 18, 2023, Mike Stump <mikestump@comcast.net> wrote:

> On Mar 15, 2023, at 11:40 PM, Alexandre Oliva <oliva@adacore.com> wrote:
>> 
>> On Mar 15, 2023, Alexandre Oliva <oliva@adacore.com> wrote:
>> 
>>> Regstrapped on ppc64-linux-gnu.  Also tested (with gcc-12) on multiple
>>> *-vxworks7r2 targets (arm, aarch64, ppc64, x86, x86_64).  Ok to install?
>> 
>> Further testing revealed a problem in my attempted use of lappend in
>> aapcs64.exp, in the previous version of the patch.  Fixed in this one,
>> retested on aarch64-vxworks7r2.  Ok to install?

> Ok.

Thanks.  Marc Poulhies pointed out I'd failed to document the new dg
bits (thanks!).  Fixed below.  I'm going to check it if there are no
objections in the next 24 hours.


[testsuite] test for weak_undefined support and add options

A number of tests that depend on weak undefined symbols fail to
require that support, and arrange to skip some targets and add special
options to others on a test-by-test basis.  Fix this by stating the
requirement explicitly, and adding a proc to return any required
options.

Others rely on weak undefined symbols only to test for the
availability of posix_memalign.  Drop that in favor of dg effective
target support for posix_memalign.


for  gcc/testsuite/ChangeLog

	* lib/target-supports.exp (add_options_for_weak_undefined):
	New.
	(check_effective_target_weak_undefined): Use it.
	(check_effective_target_posix_memalign): New.
	* doc/sourcebuild.texi: Document them.
	* gcc.dg/torture/pr53922.c: Drop skips and custom options in
	favor of effective target requirement and added options for
	weak_undefined symbols.
	* gcc.dg/torture/pr90020.c: Likewise.
	* gcc.dg/addr_equal-1.c: Likewise.
	* gcc.target/aarch64/aapcs64/aapcs64.exp: Likewise, for
	abitest.S-using tests.
	* gcc.dg/torture/pr60092.c: Likewise, but in favor of
	posix_memalign tests.
	* gcc.dg/vect/vect-tail-nomask-1.c: Likewise.
---
 gcc/doc/sourcebuild.texi                           |    9 ++++++
 gcc/testsuite/gcc.dg/addr_equal-1.c                |    5 +---
 gcc/testsuite/gcc.dg/torture/pr53922.c             |   10 +------
 gcc/testsuite/gcc.dg/torture/pr60092.c             |   12 +--------
 gcc/testsuite/gcc.dg/torture/pr90020.c             |    7 +----
 gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c     |   11 +-------
 .../gcc.target/aarch64/aapcs64/aapcs64.exp         |   17 +++++++-----
 gcc/testsuite/lib/target-supports.exp              |   28 ++++++++++++++++++--
 8 files changed, 54 insertions(+), 45 deletions(-)

diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index 80bef7f0a0e22..c430bceb33ae8 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -2697,6 +2697,9 @@ Target supports Newlib.
 GCC was configured with @code{--enable-newlib-nano-formatted-io}, which reduces
 the code size of Newlib formatted I/O functions.
 
+@item posix_memalign
+Target supports @code{posix_memalign}.
+
 @item pow10
 Target provides @code{pow10} function.
 
@@ -2759,6 +2762,9 @@ Target is a VxWorks RTP.
 
 @item wchar
 Target supports wide characters.
+
+@item weak_undefined
+Target supports weak undefined symbols
 @end table
 
 @subsubsection Other attributes
@@ -3130,6 +3136,9 @@ instructions, if any.
 
 @item tls
 Add the target-specific flags needed to use thread-local storage.
+
+@item weak_undefined
+Add the flags needed to enable support for weak undefined symbols.
 @end table
 
 @node Require Support
diff --git a/gcc/testsuite/gcc.dg/addr_equal-1.c b/gcc/testsuite/gcc.dg/addr_equal-1.c
index 35fa0102e3063..db65dea4a8d2a 100644
--- a/gcc/testsuite/gcc.dg/addr_equal-1.c
+++ b/gcc/testsuite/gcc.dg/addr_equal-1.c
@@ -1,9 +1,8 @@
-/* { dg-do run { target { nonpic || pie_enabled } } } */
-/* { dg-require-weak "" } */
+/* { dg-do run { target { { nonpic || pie_enabled } && weak_undefined } } } */
 /* { dg-require-alias "" } */
 /* { dg-options "-O2 -fdelete-null-pointer-checks" } */
-/* { dg-skip-if "" { powerpc-ibm-aix* } } */
 /* { dg-skip-if "function pointers can be NULL" { keeps_null_pointer_checks } } */
+/* { dg-add-options weak_undefined } */
 void abort (void);
 extern int undef_var0, undef_var1;
 extern __attribute__ ((weak)) int weak_undef_var0;
diff --git a/gcc/testsuite/gcc.dg/torture/pr53922.c b/gcc/testsuite/gcc.dg/torture/pr53922.c
index b3f2c1a58f830..07359d6764964 100644
--- a/gcc/testsuite/gcc.dg/torture/pr53922.c
+++ b/gcc/testsuite/gcc.dg/torture/pr53922.c
@@ -1,11 +1,5 @@
-/* { dg-do run } */
-/* { dg-require-weak "" } */
-/* { dg-skip-if "No undefined" { *-*-mingw* } } */
-/* { dg-skip-if "No undefined weak" { *-*-aix* } } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* && { ! lp64 } } } */
-/* { dg-skip-if "No undefined weak" { nvptx-*-* } } */
-/* { dg-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-do run { target { weak_undefined } } } */
+/* { dg-add-options weak_undefined } */
 
 int x(int a)
 {
diff --git a/gcc/testsuite/gcc.dg/torture/pr60092.c b/gcc/testsuite/gcc.dg/torture/pr60092.c
index 74e7c174a8323..102ba6e0d9f87 100644
--- a/gcc/testsuite/gcc.dg/torture/pr60092.c
+++ b/gcc/testsuite/gcc.dg/torture/pr60092.c
@@ -1,12 +1,7 @@
-/* { dg-do run } */
-/* { dg-require-weak "" } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* && { ! lp64 } } } */
-/* { dg-skip-if "No undefined weak" { nvptx-*-* } } */
-/* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-do run { target { posix_memalign } } } */
 
 typedef __SIZE_TYPE__ size_t;
-extern int posix_memalign(void **memptr, size_t alignment, size_t size) __attribute__((weak));
+extern int posix_memalign(void **memptr, size_t alignment, size_t size);
 extern void abort(void);
 int
 main (void)
@@ -14,9 +9,6 @@ main (void)
   void *p;
   int ret;
 
-  if (!posix_memalign)
-    return 0;
-
   p = (void *)&ret;
   ret = posix_memalign (&p, sizeof (void *), -1);
   if (p != (void *)&ret)
diff --git a/gcc/testsuite/gcc.dg/torture/pr90020.c b/gcc/testsuite/gcc.dg/torture/pr90020.c
index 657c4ccfe45c4..40035aa758e6e 100644
--- a/gcc/testsuite/gcc.dg/torture/pr90020.c
+++ b/gcc/testsuite/gcc.dg/torture/pr90020.c
@@ -1,8 +1,5 @@
-/* { dg-do run } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* || powerpc-ibm-aix* } } */
-/* { dg-require-weak "" } */
-/* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-do run  { target { weak_undefined } } } */
+/* { dg-add-options weak_undefined } */
 
 void __attribute__((noinline,noclone))
 check (int i)
diff --git a/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c b/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c
index e5bbeaede095b..ee9ab2e9d910b 100644
--- a/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c
+++ b/gcc/testsuite/gcc.dg/vect/vect-tail-nomask-1.c
@@ -1,14 +1,10 @@
-/* { dg-require-weak "" } */
-/* { dg-skip-if "No undefined weak" { hppa*-*-hpux* && { ! lp64 } } } */
-/* { dg-skip-if "No undefined weak" { nvptx-*-* } } */
-/* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
-/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+/* { dg-skip-if "No undefined weak" { ! { posix_memalign } } } */
 /* { dg-additional-options "--param vect-epilogues-nomask=1 -mavx2" { target avx2_runtime } } */
 
 #define SIZE 1023
 #define ALIGN 64
 
-extern int posix_memalign(void **memptr, __SIZE_TYPE__ alignment, __SIZE_TYPE__ size) __attribute__((weak));
+extern int posix_memalign(void **memptr, __SIZE_TYPE__ alignment, __SIZE_TYPE__ size);
 extern void free (void *);
 
 void __attribute__((noinline))
@@ -98,9 +94,6 @@ run_test ()
 int
 main (int argc, const char **argv)
 {
-  if (!posix_memalign)
-    return 0;
-
   run_test ();
   return 0;
 }
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp b/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
index 8cf9cc1e8e585..38a2c06a59560 100644
--- a/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
@@ -32,12 +32,15 @@ set additional_flags "-W -Wall -Wno-abi -fno-pie -no-pie"
 # Test parameter passing.  This uses abitest.S which relies on weak
 # symbols.
 
-if { [check_weak_available] } {
+set additional_flags_for_abitest [add_options_for_weak_undefined ""]
+set additional_flags_for_abitest "$additional_flags $additional_flags_for_abitest"
+
+if { [check_effective_target_weak_undefined] } {
     foreach src [lsort [glob -nocomplain $srcdir/$subdir/test_*.c]] {
 	if {[runtest_file_p $runtests $src]} {
 	    c-torture-execute [list $src \
 				    $srcdir/$subdir/abitest.S] \
-				    $additional_flags
+		$additional_flags_for_abitest
 	}
     }
 }
@@ -54,28 +57,28 @@ foreach src [lsort [glob -nocomplain $srcdir/$subdir/rec_*.c]] {
 
 # Test unnamed argument retrieval via the va_arg macro.  This uses abitest.S
 # which relies on weak symbols.
-if { [check_weak_available] } {
+if { [check_effective_target_weak_undefined] } {
     foreach src [lsort [glob -nocomplain $srcdir/$subdir/va_arg-*.c]] {
 	if {[runtest_file_p $runtests $src]} {
 	    c-torture-execute [list $src \
 				    $srcdir/$subdir/abitest.S] \
-				    $additional_flags
+		$additional_flags_for_abitest
 	}
     }
 }
 
 # Test function return value.  This uses abitest.S which relies on
 # weak symbols.
-if { [check_weak_available] } {
+if { [check_effective_target_weak_undefined] } {
     #   Disable -fipa-ra to prevent the compiler from generating
     #   conflicting code.
-    set additional_flags_for_func_ret $additional_flags
+    set additional_flags_for_func_ret $additional_flags_for_abitest
     append additional_flags_for_func_ret " -fno-ipa-ra"
     foreach src [lsort [glob -nocomplain $srcdir/$subdir/func-ret-*.c]] {
 	if {[runtest_file_p $runtests $src]} {
 	    c-torture-execute [list $src \
 				    $srcdir/$subdir/abitest.S] \
-				    $additional_flags_for_func_ret
+		$additional_flags_for_func_ret
 	}
     }
 }
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index fcfe290d07d71..2b31b19f0e934 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -356,6 +356,18 @@ proc check_weak_available { } {
     }
 }
 
+# return options to add to enable weak undefined symbols.
+
+proc add_options_for_weak_undefined { flags } {
+    if { [istarget *-*-darwin*] } {
+	lappend flags "-Wl,-undefined,dynamic_lookup"
+	if { [istarget *-*-darwin[89]*] } {
+	    lappend flags "-Wl,-flat_namespace"
+	}
+    }
+    return $flags
+}
+
 # return 1 if weak undefined symbols are supported.
 
 proc check_effective_target_weak_undefined { } {
@@ -365,7 +377,7 @@ proc check_effective_target_weak_undefined { } {
     return [check_runtime weak_undefined {
 	extern void foo () __attribute__((weak));
 	int main (void) { if (foo) return 1; return 0; }
-    } ""]
+    } [add_options_for_weak_undefined ""]]
 }
 
 ###############################
@@ -1154,6 +1166,16 @@ proc check_effective_target_clone {} {
     return [check_function_available "clone"]
 }
 
+# Return 1 if the target supports posix_memalign, 0 otherwise.
+proc check_effective_target_posix_memalign {} {
+    if { [istarget *-*-vxworks*] } {
+	# VxWorks doesn't have posix_memalign but our way to test
+	# can't tell as we're doing partial links for kernel modules.
+	return 0
+    }
+    return [check_function_available "posix_memalign"]
+}
+
 # Return 1 if the target supports setrlimit, 0 otherwise.
 proc check_effective_target_setrlimit {} {
     # Darwin has non-posix compliant RLIMIT_AS
@@ -2879,7 +2901,7 @@ proc check_fork_available {} {
 	# VxWorks doesn't have fork but our way to test can't
 	# tell as we're doing partial links for kernel modules.
 	return 0
-     }    
+    }
     if { [istarget cris-*-*] } {
 	# Compiling and linking works, and an executable running e.g.
 	# gcc.dg/torture/ftrapv-1.c works on now-historical hardware,
@@ -10827,7 +10849,7 @@ proc check_vect_support_and_set_flags { } {
         } else {
             set dg-do-what-default link
         }
-    } elseif [istarget "aarch64*-*-*"] {
+    } elseif [istarget aarch64*-*-*] {
         set dg-do-what-default run
     } elseif [istarget s390*-*-*] {
 	# The S/390 backend set a default of 2 for that value.